【Objective】 The purpose of this study was to investigate the prevalence status of neonatal congenital heart disease (CHD) in Ningbo City, Zhejiang Province from 2017 to 2021, and to analyze the influencing factors, so as to provide reference for preventing the risk of CHD and reduce the prevalence of CHD. 【Methods】 Using cross-sectional survey method, the neonatal data from March 2017 to December 2021 were captured from Zhenjiang Neonatal Disease Screening Center, and were analyzed by linear trend chi-square test; binary Logistic regression was used to analyze the influencing factors of CHD. 【Results】 A total of 13 156 newborns screened positive for CHD in Ningbo, Zhejiang Province, with CHD confirmed in 6 300 cases. Among these, 3 066 cases were boys (48.7%) and 3 234 cases were girls (51.3%). The prevalence rates of neonatal CHD in Ningbo city for the years 2017, 2018, 2019, 2020, and 2021 were 2.07%, 1.10%, 2.00%, 2.04% and 1.08%, respectively, with an overall prevalence from 2017 to 2021 of 1.69%. The chi-square test for the linear trend indicated a decreasing prevalence of neonatal CHD over time(χ²=178.518,P<0.001). Multivariate analysis showed that maternal age [36 to 45 years(OR=1.24), >45 years(OR=1.66)], male infants (OR=1.26), premature birth [<32 weeks (OR=1.13), 32 - 36 weeks(OR=1.54)], and being a second birth (OR=2.56) were independent risk factors for the development of CHD (P<0.05). 【Conclusions】 The prevalence of CHD in Ningbo, Zhejiang Province is higher than that of CHD in China and other cities of Zhejiang Province. Although the prevalence showed a decreasing trend over time, targeted prevention and control measures need to be implemented to reduce the prevalence of CHD.

Objective:To investigate the resistance of Culex pipiens pallens to pyrethroid insecticides in Hangzhou City, and explore the mutation of knock down resistance (kdr) gene of Culex pipiens pallens, providing scientific basis for control of Culex pipiens pallens in the region. Methods:In September 2022, larvae and pupae of Culex pipiens pallens were collected from various locations at national monitoring sites in Shangcheng District and Gongshu District of Hangzhou City. They were bred in the laboratory and their resistance to three commonly used pyrethroid insecticides (permethrin, deltamethrin and beta-cypermethrin) was determined using the adult mosquito contact tube method and larval immersion method recommended by the World Health Organization. The genomic DNA was extracted from individual adult mosquito, and kdr gene mutation was detected via PCR amplification and Sanger sequencing. Results:The 24-hour mortality rates of adult mosquitoes of Culex pipiens pallens exposed to 0.25% permethrin, 0.025% deltamethrin, and 0.025% beta-cypermethrin were 20.00% (15/75), 17.33% (13/75), and 18.67% (14/75), respectively, indicating resistance. The resistance ratios of Culex pipiens pallens larvae to permethrin, deltamethrin, and beta-cypermethrin were 27.08, 341.00, and 15.88, respectively. Among 183 adult mosquitoes that survived under the diagnostic doses of pyrethroid insecticides, 180 mosquitoes (98.36%) had mutation at the L1014 site of the kdr gene. Among 42 adult mosquitoes that died under the diagnostic doses of pyrethroid insecticides, 5 mosquitoes (11.90%) had L1014 mutation in the kdr gene. Conclusions:Culex pipiens pallens in Hangzhou City has developed varying degrees of resistance to permethrin, deltamethrin and beta-cypermethrin, with a high frequency of kdr gene mutation in resistant mosquitoes. We should strengthen the monitoring of the resistance of Culex pipiens pallens in Hangzhou City and use chemical insecticides reasonably.

Objective:To investigate the distribution and seasonal fluctuations of flies in Hangzhou, study the resistance of Musca domestica ( M. domestica) to five commonly used sanitary insecticides and changing patterns in Hangzhou and provide a basis for scientific control of flies. Methods:From April to November 2023, the cage trap method was used for ecological monitoring of flies. From May to June 2023, the swing net method was used to collect M. domestica from various districts (counties and cities) in Hangzhou. After indoor breeding, the resistance of F1 generation female adult flies to five commonly used sanitary insecticides was determined using the micro-drop method. Probit regression model was used to calculate the median lethal dose (LD 50), 95% confidence interval ( CI) and virulence regression equation. Results:In 2023, the fly density in Hangzhou was 5.99 flies/cage, with a higher density of flies belonging to the Sarcophagus family (2.39 flies/cage), making it the dominant fly species in Hangzhou. Among different monitoring points, the fly density in Linping District was relatively high (20.97 flies/cage). In different habitats, the fly density in agricultural markets was relatively high (fly density from April to November: 2.86, 5.39, 8.86, 16.86, 31.32, 6.39, 3.75 and 1.89 flies/cage). The seasonal fluctuation of fly density showed a unimodal pattern, with the higher density in August (13.45 flies/cage). The M. domestica population in Hangzhou was sensitive to dichlorvos [resistance ratio ( RR): 3.08 times]. Different degrees of resistance were developed to propoxur, deltamethrin, beta-cypermethrin, and beta-cyhalothrin. The degree of resistance from high to low was propoxur (> 336.36 times), beta-cypermethrin (906.61 times), beta-cyhalothrin (432.29 times), and deltamethrin (72.56 times). Based on the monitoring results from 2003 to 2023, the RR of dichlorvos reached the higher level in 2008 (33.47 times) and gradually decreased to a sensitive level. The resistance level of propoxur had been at an extremely high level over the years. Three types of pyrethroid insecticides all had high resistance. Conclusions:The species of flies in the Sarcophagus family are the dominant population in Hangzhou, and M. domestica has developed high resistance to four commonly used insecticides except for dichlorvos. The use of physical control techniques is advocated to reduce the use of chemical pesticides, and prevent the continuous increase of resistance in M. domestica.